title: Drusen measurements comparison by fundus photograph manual delineation versus optical coherence tomography retinal pigment epithelial segmentation automated analysis.
abstract: OBJECTIVE
  To compare drusen measurements obtained from color fundus and infrared retromode photographs with those derived from spectral-domain optical coherence tomography.
  
  
  METHODS
  Drusen lesions identified on the planar (color and infrared) imaging modalities were manually segmented by two independent graders using previously described reading center software to produce quantitative measurements of drusen area and number. The corresponding volume Cirrus OCT datasets were analyzed using commercial retinal pigment epithelium analysis algorithms to segment the retinal pigment epithelium band and estimated the drusen area. Drusen numbers were extracted from retinal pigment epithelium elevation maps. Intraclass correlation coefficients assessed agreement between graders; graders' average measurements were compared with optical coherence tomography (OCT) using paired T-tests.
  
  
  RESULTS
  Excellent agreement between graders was observed (r = 0.951-0.974). No statistical difference was found in the area values obtained by color (0.85 ± 0.26 mm(2), P = 0.43) or retromode (1.15 ± 0.32 mm(2), P = 0.35) compared with those obtained by OCT (0.98 ± 0.28 mm). The number of drusen identified by OCT (13.15 ± 3.19) was significantly lower than that determined by manual segmentation of color (53.7 ± 13.18) and retromode (100.13 ± 16.18) images.
  
  
  CONCLUSIONS
  Although the number of drusen individualized by commercial OCT algorithms is significantly lower than by planar fundus imaging modalities, the OCT-measured drusen area is not affected, suggesting that the algorithm counts confluent drusen as a single drusen.
authors.affiliation: *Doheny Eye Institute, Los Angeles, California; †Department of Ophthalmology, Federal University of Sao Paulo, São Paulo, Brazil; ‡Department of Ophthalmology, Evangelical Hospital of Curitiba, Curitiba, Brazil; and §Department of Ophthalmology, Keck School of Medicine of the University of Southern California, Los Angeles, California.
authors.forename: Bruno
authors.initials: B
authors.lastname: Diniz
authors.forename: Ramiro
authors.initials: R
authors.lastname: Ribeiro
authors.forename: Florian M
authors.initials: FM
authors.lastname: Heussen
authors.forename: Mauricio
authors.initials: M
authors.lastname: Maia
authors.forename: Srinivas
authors.initials: S
authors.lastname: Sadda
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D005260:Female; D057092:Geographic Atrophy / Q000175:diagnosis*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010781:Photography / Q000379:methods*; D011446:Prospective Studies; D015593:Retinal Drusen / Q000175:diagnosis*; D055213:Retinal Pigment Epithelium / Q000473:pathology*; D041623:Tomography, Optical Coherence / Q000379:methods*